Zhengzhou, home to more than 12.6 million people in Central China's Henan Province, pressed the "pause button" from Wednesday until next Tuesday after the city reported nine confirmed cases and 24 asymptomatic infections on Tuesday.

The city stopped all group gathering activities, asking residents in downtown areas to stay inside their residential compounds. Each household can have one person going out every day to purchase basic supplies with a negative COVID-19 test result from the previous 24 hours.

Zhengzhou also suspended the reopening of kindergartens and schools, requiring people to work from home with the exception of those working for public services, guaranteeing residents' life and on city operations.

People taking public transportation, including buses, subways and taxis, will have to show a negative COVID-19 test from the previous 24 hours.

Eight downtown districts in Zhengzhou started three rounds of citywide nucleic acid screening from Wednesday to Friday. Those who did not receive the test within 24 hours will find their health QR code turn yellow, which means they will be not able to use public facilities or enter public places where a green code is required for access.

The government of Zhengzhou said on a press conference on Tuesday that the city will try to put the overall risk of the epidemic under control in a week.